Choosing the best thermal paste may sound simple, but a dizzying array of options can turn this seemingly easy choice into a time-consuming task. Thermal paste is designed to minimize microscopic air gaps and irregularities between the surface of the cooler and the CPU’s IHS (integrated heat spreader), the piece of metal which is built into the top of the processor.

Good thermal paste can have a profound impact on your performance, because it will allow your processor to transfer more of its waste heat to your cooler and continue operating at a high clock speed for longer while a mediocre product will force your system to throttle in order to avoid overheating. Even the best CPUs are made better by good thermal paste. 

Performance enthusiasts often swear by a favorite brand of paste, but new recipes crop up from time to time. We’ve conducted extensive testing of some of the top thermal pastes on the market, and if you’re on the hunt for more exotic pastes that are off the beaten path, we also have plenty of historical data below covering 90 different pastes (and yes, we’ve even tested toothpaste).

Thermal paste can go by many names, such as “thermal compound,” “thermal grease,” or “TIM” (Thermal Interface Material). Most pastes are comprised of ceramic or metallic materials suspended within a proprietary binder which allows for easy application and spread as well as simple cleanup. 

These thermal pastes can be electrically conductive or non-conductive, depending on their specific formula. Electrically conductive thermal pastes can carry current between two points, meaning that if the paste squeezes out onto other components, it can cause damage to motherboards and CPUs when you switch on the power. A single drop out of place can lead to a dead PC, so extra care is imperative. 

Liquid metal compounds are almost always electrically conductive, so while these compounds provide better performance than their paste counterparts, they require more focus and attention during application. They are very hard to remove if you get some in the wrong place, which would fry your system.

In contrast, traditional thermal paste compounds are relatively simple for every experience level. Most, but not all, traditional pastes are electrically non-conductive. We have a detailed breakdown of the best methods for applying thermal paste here. 

Here are the best thermal pastes, along with our complete test results. Keep in mind that you don’t always get what you pay for as some budget pastes come awfully close to or overtake their more-expensive competitors.

Best Premium (Standard) Thermal Paste

Often hanging close to, but not overtaking, liquid metal compounds in our tests, PromilaTech PK-3 Nano Aluminum paste is a moderately viscous thermal compound integrated with aluminum and zinc oxide. The paste provides good stability, making it easy to apply to all surfaces as well as simple to clean up. You really can’t go wrong with this paste — it is sufficient for most CPU applications.

Thermal Grizzly Kryonaut is a mildly viscous thermal compound with good stability, making it simple to work with while also resisting drips and runs. This paste is very easy to apply and clean up, making it a favorite among system builders.

Best Budget Thermal Paste

Noctua’s NH-H1 is a relatively viscous and stable compound that applies easily and allows for easy clean-up. A screw-on cap syringe maintains compound longevity to prevent drying and is priced as an attractive paste for those on a budget. You really can’t go wrong with this paste — it is sufficient for the majority of builds.

Gelid GC-Extreme is a moderately viscous compound, making it very stable during application and it spreads consistently, although it requires slow consistent pressure on the syringe plunger for correct placement. This TIM is relatively easy to use and simple to clean up.

Thermal Grizzly Conductonaut liquid metal thermal compound has a very thin, runny consistency and is applied to the CPU integrated heat spreader with a syringe delivery system and capillary needle applicator tip. Excess material can be siphoned off using a special extraction tip (by pulling the syringe plunger to withdraw excess liquid metal).

CoolLaboratory Liquid Pro is a liquid metal compound that is applied with a syringe and capillary tip to the CPU integrated heat spreader, and it ships with a scouring pad and alcohol swab for prep and cleanup. 

Application and spreading of the liquid metal are made easier with cotton swabs and generous pressure for even distribution. Liquid metal can cause reactions with some metals, such as aluminum, and some reports of reactions with copper are also documented by end-users.

Best Budget Liquid Metal Thermal Paste

For a compound that costs less than half as much as leading competitors , Phobya’s Liquid Metal Compound LM offers impressive performance, often besting the the CoolLaboratory Liquid Pro or Thermal Grizzly Conductonaut in our tests.

Liquid Metal Compound LM ships as a syringe with a capillary applicator tip. Spreading the compound is made easier with cotton swabs and generous pressure to develop a consistent coating on the CPU IHS. Can cause reactions with aluminum and other metals.

Thermal Paste Performance Rankings

Here’s a breakdown of our recent testing, and we’ll be adding new pastes to this list over the coming weeks and months. A bit further down, you’ll find our original round of testing with 85 different pastes, some of which we’ve revisited in this new performance hierarchy. That should give you a good idea of how other pastes that we haven’t retested yet would compare to the newer pastes. 

We’ll go into our breakdown of how we test these thermal pastes below, but the key takeaway here is that a single thermal compound can perform differently based upon several variables, such as what type of cooler and mount you use. To cover all the bases, we’ve tested every thermal paste with three variables: 

• Low-tension Noctua NH-D15 mounting to model an air cooler without a backplate (like an Intel stock cooler, or push-pin coolers)
• High-tension Noctua NH-D15 mounting to model higher-end air coolers with a backplate
• High-tension mounting with an all-in-one (AIO) liquid cooler

Below you’ll find the temperatures we measured on our standardized test bench, and as always, lower temperatures are better. We’ve also included value charts in the album below as well. 

Thermal Paste Test Results

As shown in the slides above, the outcome of the different testing scenarios resulted in some interesting comparisons among the compounds. We’ll look at the overall thermal load averages for each, as well as the relative performance value of each in terms of price-per-gram.

All In One (AIO) Liquid Cooler – High Tension Mount

It’s no surprise that the liquid metal compounds once again sit atop the thermal comparison. Still, a 6C difference between all 15 thermal compounds tested shows there isn’t a lot of variation, even with a 360 all-in-one cooler with a push+pull fan setup for performance. 

Key Takeaways

Thermal compounds might always be compared and debated over, but the simple fact remains: PC system building needs thermal compounds to effectively dissipate thermal loads. Without them, our beloved gaming and content-producing machines would struggle to keep components cool during heated frag sessions, heavy workstation computations, or just simply browsing the web. 

Not every system will need the most expensive compound, so even the most budget-minded system builders can rest easy knowing that even lower-cost pastes can still prove very effective. You can see our historical testing results with far more pastes after the test setup. 

Test System Configuration and Testing Methods

For our thermal compound tests, we use the same hardware, overclock, and configuration for each and every test to minimize environment variables in our testing. 

We tested each thermal paste with a low-tension air cooler mount, high-tension air cooler mount, and a high-tension AIO liquid cooler mount. Each application was given a 1-hour burn-in using Prime95 with ten load and cooling cycles over the course of the hour; six minutes each with a ten-second cool-down between. Each testing load session was then executed for a one-hour load period, again using Prime95. 

For the air cooling low- and high-tension tests, we used a large Noctua NH-D15 air cooler. We created the low tension mount environment by torquing the mounting screws to 1.13 Nm (10 in/lbs). 

The low tension mounting tests help simulate cooler installs that might not use a backplate (like push-pin coolers) or those that do not allow high tension and compression across the CPU integrated heat spreader. Also, repeated tests are not consistently possible with push-pin mounted coolers:  The pins can degrade after several mount cycles, which meant we needed to simulate these to maintain consistent test results.

Our high-tension air cooler mount involved tightening the mounting screws fully to the mounting plate and shows thermal paste performance with air coolers with backplates that allow for tighter mounting.

We used the EK-AIO Elite 360 D-RGB for the liquid cooling tests with all fans in a push+pull configuration. We performed these tests with the AIO pump block fully tensioned (tightened). We didn’t test the AIO with a low-tension mount because liquid coolers almost always employ a backplate that allows a high-tension mount.

Overall, each compound was evaluated and stressed over a regimen cycle covering six hours with two different coolers and different mounting tensions, making for no less than 90 hours of compound testing for our initial round of tests. 

Legacy Thermal Paste Testing – 85 Pastes Tested

Here’s our legacy thermal paste testing chart that we generated back in 2017. As you’ll notice, many of the same popular pastes in 2017 are still on the market, making it into our new round of 2021 testing. 

We do have new testing equipment for our updated tests, such as a more modern CPU, motherboard, and coolers for our tests, but we adhered to the same test methodology employed in these prior tests. That means that you can use these legacy tests as a decent approximation of how the newer pastes compare to the older pastes, too. 

We’ll be adding more thermal pastes to our new hierarchy; stay tuned.